The current study sought to examine how infant negative affect changes with age and the factors that underlie that change (i.e., infant locomotor onset and emotion socialization). Participants included white, middle-class mothers ages 18 to 44, as well as their first-born infants at 6 months (all prelocomotor) and 8 months (half remained prelocomotor) of age. Videos of 20 mother-infant dyads taken at home were coded for maternal affect, infant affect, and prohibition scenes. Four, 2-way analyses of variance indicated that (1) the number of prohibitions increased with age for locomotor infants only, (2) the degree to which infant negative affect is concentrated around prohibitions increases with age specifically for locomotor infants and (3) a positive correlation between infant negative affect and the number of prohibitions, suggesting that locomotion may play an organizing role in the socialization of emotion.
Cioni '95, Jennifer L., "Socialization of Emotion: The Role of Parental Discipline in Infant Anger Expression" (1995). Honors Projects. 97.